George Kyratas, owner of Hathaway's Restaurant and Lounge in Cinnaminson, N.J., has seen the changes during his 26 years in the family's business.

In fact, he converted part of his diner into a lounge because the appeal for old-fashioned diner fare has slipped.

Consider, for instance, the demand for these homely diner classics: Liver and onions, snapper soup, turkey croquettes and creamed chipped beef on toast.

Going, going, nearly gone.

Let's start with unloved liver, a name that automatically sends a shiver down the spines of some eaters.

Inexpensive beef liver has a strong smell and assertive taste that turns some folks off, even when more delicate and costlier calves' liver is what is featured on the menu.

"But that was comfort food for the older people. My parents stopped eating it, but my grandparents loved it. They are slowly dying away. Customers are ordering it less and less," said Kyratas.

He took liver off his menu seven years ago.

George Vallianos, the former owner of the Elgin Diner in Camden, N.J., used to serve a lot of liver when he was in the kitchen years ago.

But demand is fading fast for two reasons: First, most people don't know how to cook liver. There are also health concerns.

"Everything about it (liver) is cholesterol," he said.

He's right: a single slice of liver delivers more than 90 percent of the suggested cholesterol an adult should consume, according to most references.

Still, that doesn't stop everyone from ordering calves' liver at the Penn Queen Diner, a Pennsauken, N.J., mainstay in the same family for 45 years. Managing partner Manny Konstantinides said the dish typically draws about 10 orders a day and double or more when it is a featured special, as it has been on several recent Wednesdays.

"There isn't a day that goes by without someone ordering it," said Konstantinides.

What is that exactly?

If liver is a throwback dish entering the history books, that's also true for the croquettes, which can be made from either chicken or turkey.

Once upon a time, croquettes were a favorite way of dealing with leftovers, though they've fallen out of favor, likely because traditional versions included deep-fat frying to ensure a crisp breadcrumb crust.

Of course, nowadays if you want a croquette badly enough, you can just heat up a frozen one before drowning it in canned gravy - tricks many restaurants that still serve croquettes resort to when an order comes in.

"No self-respecting diner would do that," said Vallianos, though of course some do exactly that.

Another throwback item that has disappeared from many diner menus or been replaced with a canned version is snapper soup - not snapper the fish, but soup made from the meat of snapping turtles.

Thick, rich, and resonate with layers of flavors from a mix of spices including cloves, there was a time when nearly every diner in the Philadelphia region made its own version, served up with a side of sherry to customize the flavor.

No more. Even if snapper soup is on the menu, best ask if it is house-made if you care about eating the real thing.

"Everyone had it," recalled Vallianos. "But it is expensive, takes time and is labor intensive. And there's not enough call or demand for it."

At Ponzio's in Cherry Hill, N.J., they still make snapper soup from scratch, pretty much just as they have for 49 years, said John Fifis, one of the owners.

The main difference now is the snapping turtles come in already butchered every Monday morning. Back in the day, local providers brought in live turtles.

"We're not selling as much as we did five or 10 years ago," said Fifis, a Culinary Institute of America alumnus who oversees Ponzio's kitchen and makes the soup.

Chip off the old menu

There is one throwback diner food that, while not as ubiquitous as it once was, remains fairly easy to find.

And while it can be made from a product in a pouch, most diners still make their own creamed chipped beef on toast or, in diner lingo, SOS ($%^& on a shingle).

Kyratas thinks the dish's durability comes from its military background.

Creamed chipped beef - air-dried and paper thin salted beef in a white sauce - keeps soldiering on, but it is in retreat, according to Joann Kalavrouziotis, co-owner of the Westmont Diner.

"We sell maybe 10 to 15 orders a day, mostly to men. Men eat differently than women. People are trying to eat more health consciously and it does not qualify as a health food," she said.

And while I agree, I finished my SOS order at the Westmont Diner and left the home fries behind on the plate as a nod to my health.